A murder investigation has been launched following the brutal stabbing of 18-year-old Stefan Appleton in Canonbury on Wednesday.

The teenager was knifed repeatedly with what witnesses have said was a large machete at about 6pm in Caldy Walk.

He was taken to an east London hospital but was pronounced dead at 7.45pm.

Police say Stefan was with friends in Nightingale Park when he was attacked by the pillion passenger of a moped who then climbed back on to the vehicle which made off along Nightingale Road.

The moped involved is described as having a clear front screen and displayed an L plate to the rear. The pillion passenger was wearing dark clothing and a dark helmet.

Police said that extra officers were on the streets carrying out targeted patrols.

DCI Jones said: “I’m very keen to hear from everyone who was in the area of Caldy Walk and Nightingale Park on Wednesday, 10 June, especially anyone who witnessed the attack on the victim or who has information in relation to the moped.”

“We are also keen to hear from anyone who saw or heard anything suspicious or who has information that could assist the investigation.”

Chief Superintendent Catherine Roper, Islington Borough Commander, said: “A murder investigation has been launched.

“My officers are supporting the Homicide and Major Crime Command.

“I would like to assure the local community that we are doing all that we can following this tragic incident. We have extra officers on the street carrying out targeted patrols and have increased the number of high visibility reassurance patrols conducted across the borough to ensure all those within the community feel safe.

“My officers are actively targeting offenders on the borough and we will arrest and bring to justice those intent on breaking the law in Islington.”

Witnesses or anyone with information are asked to call the incident room on 020 8345 3734 or call Crimestoppers anonymously on 0800 555 111.